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Updated: Jun 1, 2026
Proton Therapy Delivery and Its Clinical Application in Select Solid Tumor Malignancies
Published on: February 6, 2019
Pituitary hormone dysfunction after proton beam radiation therapy in children with brain tumors
Vidhya Viswanathan1, Kamnesh R Pradhan, Erica A Eugster
1Department of Pediatrics, Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, Indiana, USA. vids722@gmail.com
Insights
Pediatric brain tumor patients receiving proton beam (PB) radiation therapy showed a high rate of endocrine dysfunction. Combined conventional and PB irradiation led to faster dysfunction and higher doses compared to PB radiotherapy alone.
Area of Science:
- Pediatric Oncology
- Radiation Oncology
- Endocrinology
Background:
- Endocrine dysfunction is a significant concern for pediatric patients treated for brain tumors.
- Proton beam (PB) radiation therapy offers potential benefits but requires careful evaluation of its endocrine sequelae.
Purpose of the Study:
- To characterize endocrine dysfunction in pediatric brain tumor patients treated with PB radiation therapy.
- To compare endocrine outcomes between PB radiotherapy alone and combined conventional plus PB irradiation.
Main Methods:
- Retrospective review of medical records for pediatric patients (≤18 years) treated with PB radiation therapy for brain tumors (2000-2008).
- Analysis of patient demographics, tumor type, treatment modalities, radiation doses, and endocrine dysfunction.
- Comparison of endocrine sequelae between PB-only and conventional plus PB irradiation groups.
Main Results:
- Thirty-eight patients were identified; 31 underwent endocrine evaluation.
- No significant difference in the rate of endocrine dysfunction between PB-only (47%) and conventional plus PB (33%) groups.
- PB-only group received lower radiation doses (cobalt gray equivalents) and developed pituitary hormone deficiencies later than the combined group.
Conclusions:
- High rates of endocrine sequelae were observed in pediatric brain tumor patients treated with PB radiation therapy.
- Combined conventional and PB irradiation was associated with faster endocrine dysfunction onset and higher radiation doses.
- Prior surgery and chemotherapy are additional risk factors; further prospective studies are needed.
Objective:
To characterize endocrine dysfunction in pediatric patients with brain tumors who received proton beam (PB) radiation therapy and to compare those treated with PB radiotherapy only versus combined conventional and PB irradiation.
Methods:
A retrospective review of medical records of patients ≤18 years of age who received PB radiation therapy for a brain tumor between 2000 and 2008 was performed. Variables analyzed included patient demographics, tumor type, therapeutic modalities, radiation doses, and types and timing of endocrine dysfunction.
Results:
Thirty-eight patients were identified, of whom 31 (19 boys and 12 girls; mean age, 11.9 ± 3.3 years) had undergone endocrine evaluation. Of these patients, 19 received PB radiotherapy only and 12 received conventional plus PB irradiation. Before irradiation, a cranial surgical procedure was performed in 28 study subjects, and 22 received chemotherapy. The mean duration of follow-up after radiation therapy was 1.8 ± 0.8 years. Nine patients (47%) in the PB only group and 4 (33%) in the conventional plus PB group developed endocrine dysfunction (no significant difference) after cranial irradiation. Children with endocrine sequelae treated with PB irradiation alone received fewer cobalt gray equivalents than those treated with conventional plus PB irradiation (5,384 ± 268 versus 5,775 ± 226, respectively; P<.02), and pituitary hormone deficiencies were detected later during follow-up in those who received PB radiotherapy only versus conventional plus PB irradiation (1.17 ± 0.4 years versus 0.33 ± 0.11 year, respectively; P<.01).
Conclusion:
A high rate of endocrine sequelae was seen in our study. Children with brain tumors treated with conventional plus PB irradiation developed endocrine dysfunction faster and received a higher radiation dose than those receiving PB radiotherapy only. Prior surgical treatment and chemotherapy were additional risk factors. Large prospective studies are needed to evaluate further the incidence of endocrine sequelae after PB irradiation in children.
